ADU Construction in Orinda CA — Accessory Dwelling Units | Quartz Construction
Quartz Construction & Remodeling builds ADUs (Accessory Dwelling Units) in Orinda, CA. We are a full-service ADU contractor serving Contra Costa County — handling design, permits, construction, and final inspections for new detached ADUs, garage conversion ADUs, and attached ADUs. CSLB #1003436. Call (650) 749-7436 for a free ADU estimate in Orinda.
ADU Types We Build in Orinda, CA
Industry Resources & Standards:
- Detached ADU (Backyard Cottage): A fully independent new structure built in the backyard of your Orinda property. Detached ADUs in Contra Costa County range from 300 to 1,200 sq ft and are the most valuable addition for rental income or multigenerational living. They require their own foundation, utility connections, and full compliance with Orinda Building Department requirements.
- Attached ADU (Home Addition): An addition connected to the main house but with a separate entrance, kitchen, and bathroom. Popular in Orinda neighborhoods where the backyard is limited. Shares foundation and utility connections with the main home, reducing cost.
- Garage Conversion ADU: Converting an existing attached or detached garage into a living unit. The most cost-effective ADU option in Orinda because the structure, foundation, and utilities already exist. Requires insulation, drywall, plumbing for a kitchen and bathroom, and HVAC upgrades.
- Junior ADU (JADU): A unit created within the existing primary dwelling (usually a bedroom suite) up to 500 sq ft with an efficiency kitchen. JADUs have a streamlined permit process and are the fastest and least expensive way to create an ADU in Orinda. Owner-occupancy is required on the property.
- ADU Over Garage: A second story unit built on top of an existing single-story detached garage. Common in Contra Costa County neighborhoods with large garages. Requires structural engineering to ensure the existing garage can support the added load.
ADU Cost in Orinda 2025
| ADU Type | Size | Cost Range |
|---|---|---|
| JADU (Junior ADU within home) | Up to 500 sq ft | $60,000 – $120,000 |
| Garage Conversion ADU | 200 – 600 sq ft | $80,000 – $160,000 |
| Attached ADU (home addition) | 300 – 800 sq ft | $150,000 – $280,000 |
| Detached ADU (new construction) | 400 – 800 sq ft | $180,000 – $350,000 |
| Detached ADU (1,200 sq ft max) | 1,000 – 1,200 sq ft | $280,000 – $500,000 |
ADU Rules in Orinda
Orinda follows California state ADU law (AB 68, SB 9, AB 881), which requires local jurisdictions to allow ADUs on single-family and multi-family lots with ministerial approval for qualifying projects.
ADU Rental Income in Orinda
The average ADU rental income in Contra Costa County is $2,000-$3,500/month for a studio or 1-bedroom unit and $2,500-$4,500/month for a 2-bedroom unit. Orinda’s strong rental market means a $200,000-$300,000 ADU investment can generate $25,000-$42,000 in annual rental income — a 8-14% cash-on-cost return. Many Orinda homeowners also use ADUs for multigenerational living, housing aging parents while adding home value.
Get a Free ADU Estimate in Orinda
Quartz Construction builds ADUs throughout Orinda and Contra Costa County. We handle design, permits, construction, landscaping, and final inspections — a complete turnkey ADU solution. CSLB #1003436 | BBB A+ | 4.9 Stars. Call (650) 749-7436.
What Our Clients Say
Join hundreds of happy Bay Area homeowners who trusted Quartz Construction & Remodeling for their projects.
Posted on Google
Yogesh AhujaTrustindex verifies that the original source of the review is Google.
I got my front yard, back yard and deck work done by Ohad and his team. They did excellent work. They are very professional, delivered project in time and are very flexible too. I'll hire them anytime for my future projects.Posted on Google
SHIN NAGAKURAWe hired Quarts Construction to transform our backyard into a covered outdoor living space, and the entire project was completed in just two weeks from start to finish. The result exceeded our expectations. Our goal was to create a space that would be comfortable even on rainy days while remaining bright, open, and airy. Quarts delivered exactly that. The craftsmanship and attention to detail were outstanding. From Ohad’s initial design recommendations to his hands-on project management throughout the project, everything was handled professionally and efficiently. Every member of the crew worked hard, took pride in their work, and was a pleasure to work with. The finished patio feels like a natural extension of our home and has completely transformed how we use our backyard. We are extremely satisfied with the outcome and would not hesitate to hire Quarts Construction again for future projects. Highly recommended.Posted on Google
Tricia CashmanThe best contractor I’ve ever worked with. They were very professional, clean and their work was flawless. The owner was very involved and the communication and follow through was amazing. highly recommendPosted on Google
Dena Wood LebovitzOhad was fantastic! 6 years we have had a hole in our ceiling from a plumbing repair. Ohad called back the same day, came out and assessed a good price and complete the work quickly. Ceiling looks great. No seams and even painted the ceiling after texturizing. So happy!!Posted on Google
oritavr1My husband and I couldn't be happier with the fantastic job Ohad and his team did on our backyard renovation and pergola project! From start to finish They provided vision, design, and fast installation. I sent several inquiries and scheduled appointments, and to be honest, Quartz Construction did not give the cheapest option. However, I was impressed by the dedication and sincerity Ohad showed me and my husband on our first appointment. He came ready to show us the service they offer. I had a design drawn on a tiny piece of paper of a vision I was looking for my backyard, and he created a "blueprint" based on my vision, providing measurements to make it official. If you're looking for a team that delivers high-quality work and truly cares about their customers, I highly recommend them.Posted on Google
Tomer MishliWe had an amazing experience with Quartz Construction for our garage conversion ADU. The entire process was smooth and stress-free—they made everything incredibly easy for us from start to finish. Our project manager, Ohad, was fantastic to work with. He was always available, professional, and made sure everything ran smoothly. On top of that, they also completed a full backyard renovation, and the results exceeded our expectations. The quality of work and attention to detail were outstanding. Highly recommend them to anyone looking for a reliable and professional construction company!Posted on Google
Ted MorrisonWe hired Ohad and his crew for a home addition, and they did a fantastic job. The new area feels like it’s always been part of the house. Great craftsmanship and smooth process.Posted on Google
Danielle GarciaOhad was instrumental in making our balcony project a success. The structure is strong, the design is beautiful, and we now have an extra space to unwind and enjoy our view.Posted on Google
Sanchers Joss54The process was smooth, the details were spot-on, and the result is modern and super functional.We love our new kitchen!Posted on Google
Nathan PaleWe wanted a lovely deck, and Ohad built it for us. The work is excellent, and the design complements our house. His team arrived on time, acted professionally, and cleaned everything before leaving. We were happy with the whole experience.Posted on Google
Ramon ChanelWe had been wanting to remodel our kitchen for years, and Ohad finally made it happen. From the initial design to the final installation, he made sure everything was executed perfectly. The new kitchen is functional, modern, and truly a dream come true!Posted on Google
Lida AntonianQuartz Construction and Ohad Maloul rebuilt my 1200 sf deck with FiberOn composition decking in 3 weeks. The crew ( Ivan, Carlos, Rubin, Steven) is professional, highly trained with exemplary workmanship and aesthetic design. Ohad is an experienced project manager with effective communication skills. I appreciate the beautiful deck they created!Posted on Google
Josue KennethOur new patio is stunning! Ohad’s design is perfect, the materials look luxurious, and the crew delivered with professionalism and skill.Posted on Google
Seth CMy experience was so good it has me actually excited to find a new project to get started on, which is a nice change from the dread I felt when I needed a two room remodel done. Ohad is the kind of person I feel confident is going to make it right. He came in on time, on budget, and did a few things for me that weren't on the original quote, and it was no issue. THis was a remodel for my mother, and I feel confident recommending him because he took great care of her, listened to her, and made sure that she LIKED what was done, not just felt satisfied. When I pointed oout a few things that needed adjusting, there was no defensiveness or difficulty, it was all hands on deck get it done and get it done fast. My project was a moderate budget, but when we got to know him we added on another project because it was going so well we started to think aspirationally. I am very, very happy with the work and would gladly serve as a reference. If you have a home remodel to do, they are trustworthy and reasonable. They also moved fast! I look forward to working with them again, and how many contractors make you feel that way?Posted on Google
Perry FinchWe’re so happy with the work Hila and her team did on our home addition. The new space flows beautifully with the existing structure, and the quality is clear in every finish. Finished on schedule and stress-free.Posted on Google
Joy RutherWorking with Ohad on our full home remodel was an incredible experience. He helped us through every decision and made sure everything turned out exactly how we envisioned. The team was easy to communicate with and super detail-focused. We still can’t believe how beautiful our home looks!Posted on Google
Ajay MukhopadhyayWe recently worked with Quartz Construction (Owner: Ohad) for a construction project to remodel our Bathroom and we couldn’t be more pleased with the results. From start to finish, their team demonstrated professionalism, and exceptional craftsmanship. They maintained clear communication throughout the project, kept us informed of progress and any potential changes, and delivered everything on time and within budget. Their quality of work is outstanding — every detail was handled with care and precision. What stood out most was their commitment to customer satisfaction. They were responsive to our questions, respectful of our space, and ensured that the final outcome matched our vision perfectly. If you're looking for a reliable, skilled, and trustworthy construction contractor, I wholeheartedly recommend Quartz Construction ( Ohad and his team) .They exceeded our expectations in every way. AjayPosted on Google
debbie curleyI had a fantastic experience working with Quartz Construction And Remodeling. Ohad Maloul the owner was professional communicative and a pleasure to work with from start to finish. His team repaired and painted my backyard pergola and the quality of their work was truly excellent. They were always on time, friendly and responsive to any questions I had throughout the process. I appreciated the clear communication and attention to detail. I’m excited to work with Ohad and his team on future projects and highly recommend them to anyone looking for reliable, high-quality construction or remodeling services.Posted on Google
Harry LewisHila managed our balcony addition project with care and precision. The design complements our home perfectly, and the build quality is outstanding. She communicated every step and made the whole process easy. We’re thrilled with the result!Posted on Google
Qi LeiI had the chance to work with Ohad and his construction team on a recent home project, and I was really impressed. Ohad is professional, easy to communicate with, and genuinely cares about the quality of the work. The crew showed up on time, kept the work area clean, and finished the job on schedule. It’s hard to find contractors who are reliable and transparent these days, but Ohad delivered on everything he promised. Would definitely recommend if you’re looking for someone who takes pride in their work and keeps things straightforward.Posted on Google
Boris TyronWe’re so happy with the work Quartz Construction did on our backyard. Ohad’s team designed and built a gorgeous deck and patio that turned the area into a dream space. The quality and detail are fantastic. Highly recommend!Posted on Google
Gloria CollinQuartz Construction built the most beautiful pergola in our backyard, thanks to Ohad. He was easy to work with, listened to our needs, and delivered a structure that’s both stylish and durable. We now have a shaded space where we can relax and entertain guests.Posted on Google
Dustin WalshThey built a beautiful, durable pergola that fits our outdoor space perfectly. Hila paid close attention to both style and quality. We now have the perfect spot for lounging, gatherings, and enjoying every season.Posted on Google
Paul WilinsWe feel incredibly lucky to have worked with Hila. She made the ADU process simple and stress-free, handling everything with care and professionalism. The final space is perfect—efficient, elegant, and exactly what we hoped for. Big thanks to her and the whole crew!Verified by TrustindexTrustindex verified that these reviews were published on Quartz Construction's Google Business Profile. Learn more
Professional Resources & Regulations
- California Contractors State License Board (CSLB) — Verify contractor licenses
- City of San Jose Building Permits — Permit requirements & inspections
- ENERGY STAR — Energy-efficient materials & standards
Related Services from Quartz Construction & Remodeling
Licensed contractor CSLB #1003436 · Serving San Jose, Santa Clara, Sunnyvale & Bay Area · Contact us for a free estimate.
What our clients say on Google
Verified reviews from our Google Business Profile. See all reviews on Google.
Posted on GoogleYogesh AhujaI got my front yard, back yard and deck work done by Ohad and his team. They did excellent work. They are very professional, delivered project in time and are very flexible too. I'll hire them anytime for my future projects.Posted on GoogleSHIN NAGAKURAWe hired Quarts Construction to transform our backyard into a covered outdoor living space, and the entire project was completed in just two weeks from start to finish. The result exceeded our expectations. Our goal was to create a space that would be comfortable even on rainy days while remaining bright, open, and airy. Quarts delivered exactly that. The craftsmanship and attention to detail were outstanding. From Ohad’s initial design recommendations to his hands-on project management throughout the project, everything was handled professionally and efficiently. Every member of the crew worked hard, took pride in their work, and was a pleasure to work with. The finished patio feels like a natural extension of our home and has completely transformed how we use our backyard. We are extremely satisfied with the outcome and would not hesitate to hire Quarts Construction again for future projects. Highly recommended.Posted on GoogleTricia CashmanThe best contractor I’ve ever worked with. They were very professional, clean and their work was flawless. The owner was very involved and the communication and follow through was amazing. highly recommendPosted on GoogleDena Wood LebovitzOhad was fantastic! 6 years we have had a hole in our ceiling from a plumbing repair. Ohad called back the same day, came out and assessed a good price and complete the work quickly. Ceiling looks great. No seams and even painted the ceiling after texturizing. So happy!!Posted on Googleoritavr1My husband and I couldn't be happier with the fantastic job Ohad and his team did on our backyard renovation and pergola project! From start to finish They provided vision, design, and fast installation. I sent several inquiries and scheduled appointments, and to be honest, Quartz Construction did not give the cheapest option. However, I was impressed by the dedication and sincerity Ohad showed me and my husband on our first appointment. He came ready to show us the service they offer. I had a design drawn on a tiny piece of paper of a vision I was looking for my backyard, and he created a "blueprint" based on my vision, providing measurements to make it official. If you're looking for a team that delivers high-quality work and truly cares about their customers, I highly recommend them.Posted on GoogleTomer MishliWe had an amazing experience with Quartz Construction for our garage conversion ADU. The entire process was smooth and stress-free—they made everything incredibly easy for us from start to finish. Our project manager, Ohad, was fantastic to work with. He was always available, professional, and made sure everything ran smoothly. On top of that, they also completed a full backyard renovation, and the results exceeded our expectations. The quality of work and attention to detail were outstanding. Highly recommend them to anyone looking for a reliable and professional construction company!Posted on GoogleTed MorrisonWe hired Ohad and his crew for a home addition, and they did a fantastic job. The new area feels like it’s always been part of the house. Great craftsmanship and smooth process.Posted on GoogleDanielle GarciaOhad was instrumental in making our balcony project a success. The structure is strong, the design is beautiful, and we now have an extra space to unwind and enjoy our view.Posted on GoogleSanchers Joss54The process was smooth, the details were spot-on, and the result is modern and super functional.We love our new kitchen!Posted on GoogleNathan PaleWe wanted a lovely deck, and Ohad built it for us. The work is excellent, and the design complements our house. His team arrived on time, acted professionally, and cleaned everything before leaving. We were happy with the whole experience.Posted on GoogleRamon ChanelWe had been wanting to remodel our kitchen for years, and Ohad finally made it happen. From the initial design to the final installation, he made sure everything was executed perfectly. The new kitchen is functional, modern, and truly a dream come true!Posted on GoogleLida AntonianQuartz Construction and Ohad Maloul rebuilt my 1200 sf deck with FiberOn composition decking in 3 weeks. The crew ( Ivan, Carlos, Rubin, Steven) is professional, highly trained with exemplary workmanship and aesthetic design. Ohad is an experienced project manager with effective communication skills. I appreciate the beautiful deck they created!Posted on GoogleJosue KennethOur new patio is stunning! Ohad’s design is perfect, the materials look luxurious, and the crew delivered with professionalism and skill.Posted on GoogleSeth CMy experience was so good it has me actually excited to find a new project to get started on, which is a nice change from the dread I felt when I needed a two room remodel done. Ohad is the kind of person I feel confident is going to make it right. He came in on time, on budget, and did a few things for me that weren't on the original quote, and it was no issue. THis was a remodel for my mother, and I feel confident recommending him because he took great care of her, listened to her, and made sure that she LIKED what was done, not just felt satisfied. When I pointed oout a few things that needed adjusting, there was no defensiveness or difficulty, it was all hands on deck get it done and get it done fast. My project was a moderate budget, but when we got to know him we added on another project because it was going so well we started to think aspirationally. I am very, very happy with the work and would gladly serve as a reference. If you have a home remodel to do, they are trustworthy and reasonable. They also moved fast! I look forward to working with them again, and how many contractors make you feel that way?Posted on GooglePerry FinchWe’re so happy with the work Hila and her team did on our home addition. The new space flows beautifully with the existing structure, and the quality is clear in every finish. Finished on schedule and stress-free.Posted on GoogleJoy RutherWorking with Ohad on our full home remodel was an incredible experience. He helped us through every decision and made sure everything turned out exactly how we envisioned. The team was easy to communicate with and super detail-focused. We still can’t believe how beautiful our home looks!Posted on GoogleAjay MukhopadhyayWe recently worked with Quartz Construction (Owner: Ohad) for a construction project to remodel our Bathroom and we couldn’t be more pleased with the results. From start to finish, their team demonstrated professionalism, and exceptional craftsmanship. They maintained clear communication throughout the project, kept us informed of progress and any potential changes, and delivered everything on time and within budget. Their quality of work is outstanding — every detail was handled with care and precision. What stood out most was their commitment to customer satisfaction. They were responsive to our questions, respectful of our space, and ensured that the final outcome matched our vision perfectly. If you're looking for a reliable, skilled, and trustworthy construction contractor, I wholeheartedly recommend Quartz Construction ( Ohad and his team) .They exceeded our expectations in every way. AjayPosted on Googledebbie curleyI had a fantastic experience working with Quartz Construction And Remodeling. Ohad Maloul the owner was professional communicative and a pleasure to work with from start to finish. His team repaired and painted my backyard pergola and the quality of their work was truly excellent. They were always on time, friendly and responsive to any questions I had throughout the process. I appreciated the clear communication and attention to detail. I’m excited to work with Ohad and his team on future projects and highly recommend them to anyone looking for reliable, high-quality construction or remodeling services.Posted on GoogleHarry LewisHila managed our balcony addition project with care and precision. The design complements our home perfectly, and the build quality is outstanding. She communicated every step and made the whole process easy. We’re thrilled with the result!Posted on GoogleQi LeiI had the chance to work with Ohad and his construction team on a recent home project, and I was really impressed. Ohad is professional, easy to communicate with, and genuinely cares about the quality of the work. The crew showed up on time, kept the work area clean, and finished the job on schedule. It’s hard to find contractors who are reliable and transparent these days, but Ohad delivered on everything he promised. Would definitely recommend if you’re looking for someone who takes pride in their work and keeps things straightforward.Posted on GoogleBoris TyronWe’re so happy with the work Quartz Construction did on our backyard. Ohad’s team designed and built a gorgeous deck and patio that turned the area into a dream space. The quality and detail are fantastic. Highly recommend!Posted on GoogleGloria CollinQuartz Construction built the most beautiful pergola in our backyard, thanks to Ohad. He was easy to work with, listened to our needs, and delivered a structure that’s both stylish and durable. We now have a shaded space where we can relax and entertain guests.Posted on GoogleDustin WalshThey built a beautiful, durable pergola that fits our outdoor space perfectly. Hila paid close attention to both style and quality. We now have the perfect spot for lounging, gatherings, and enjoying every season.Posted on GooglePaul WilinsWe feel incredibly lucky to have worked with Hila. She made the ADU process simple and stress-free, handling everything with care and professionalism. The final space is perfect—efficient, elegant, and exactly what we hoped for. Big thanks to her and the whole crew!Verified by TrustindexTrustindex verified that these reviews were published on Quartz Construction's Google Business Profile. Learn more
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